Catálogo de publicaciones - libros

Wireless Sensor networks are gaining a role of importance in the research community. In this paper, we choose Imote2 to establish our testbed according to the analysis and the comparison of the hardware capabilities and software characteristics of the current WSNs products. Moreover, we present our hardware, software platforms and “30 motes” testbed to validate and evaluate our Fully Integrated Scheme of self-Configuration and self-Organization (FISCO) while further propose the rudiment of our general routing and data dissemination testbed. In the test stage, experimental results show that each mote in the network obtains the corresponding role and takes correct actions to handle every receiving message.

Sensor Web, as an extension of Sensor Networks, is expected to be used in the distributed, large-scale environment. With the help of Internet, its application can even be extended to the world wide. And in the distributed environment, a Sensor Web usually consists of different sensor networks or single sensor owned by different organizations such as research institutions, companies or even individual user. So maximizing their benefits is what the sensors most concern about. In other words, the sensors in Sensor web are rational and selfish. In this paper, we discuss the selfish problems of Sensor Web and resolve them using specific designed mechanism. We describe several scenarios of the applications in Sensor Web and consider the variable cost and value issues which are, to the best of our knowledge, first time studied in the Sensor Web. In the end, our mechanisms are proved to be truthful and can be extended to many other applications.

Position information in sensor networks is crucial for many applications. A large number of localization algorithms have been developed, however, most of them need special measurement tools and could not work well in irregularly shaped sensor networks. In this paper, we present an Enhanced DV-hop Localization Algorithm (EDLA) to deal with irregularly shaped network topology. With the same process of DV-hop, a reference node of EDLA can delimit approximate regular shaped regions as convex hulls. Based on the inclusion test within convex hulls, the expected average per-hop distance information is disseminated by qualified relay nodes and used for position estimation. Simulation results show that the proposed localization method outperforms DV-hop and PDM(proximity-distance map) in irregularly-shaped sensor networks if both the localization error and computational complexity are considered.

In this paper we focus on the survivability of wireless sensor networks, with particular emphasis on industries requirements. we develop a model to evaluate the tradeoffs between the cost of defense mechanisms for Wireless Sensor Network and the resulting expected survivability after a network attack. The model consists of three parts. The first part simulates the occurrence of attacks or incidents. The second part simulates the impact of an attack on the WSNS which depends on the type of attack and the defense mechanism installed in the network. And the third part assesses the survivability of the system which depends on the degree of its degradation after the attack. We demonstrate through simulation the model’s effectiveness in mitigating attacks.

Some of the routing algorithms in mobile ad hoc networks use multiple paths simultaneously. These algorithms can attempt to find node-disjoint paths to achieve higher fault tolerance capability. By using node-disjoint paths, it is expected that the end-to-end delay in each path should be independent of each other. However, because of natural properties of wireless media and medium access mechanisms in ad hoc networks, the end-to-end delay between any source and destination depends on the pattern of communication in the neighborhood region. In this case some of the intermediate nodes should be silent to reverence their neighbors and this matter increases the average of end-to-end delay. To avoid this problem, multi-path routing algorithms can use zone-disjoint paths instead of node-disjoint paths. Two routes with no pair of neighbor nodes are called zone-disjoint paths. In this paper we propose a new multi-path routing algorithm that selects zone-disjoint paths, using omni-directional antenna. We evaluate our algorithm in several different scenarios. The simulation results show that the proposed approach is very effective in decreasing delay and packet loss.

The use of proxies is commonplace in today’s MANETs, where they are used for a huge variety of network services. However the main problem of using proxies is that the end-to-end nature of the communication is broken. This leads to some severe security problems. One of the main questions that arise is how content caching by intermediaries can be done when end-to-end security is required.

In this paper, we will address the research issues of when and how end-to-end security, like confidentiality and authenticity can be preserved, in mobile ad hoc network communications, when having one or more cache proxies and router nodes in the data path.

We propose a solution for an encryption scheme based on Asymmetric Cipher Sequence which allows to an intermediary nodes to cache data and convert the ciphertext for one person into the ciphertext for another person without revealing the secret decryption keys or the plaintext.

Implementation results shows that we can simultaneously achieve high encryption through a wireless links.

We have developed a self-healing key distribution scheme for secure multicast group communications for wireless sensor network environment. We present a strategy for securely distributing rekeying messages and specify techniques for joining and leaving a group. Access control in multicast system is usually achieved by encrypting the content using an encryption key, known as the group key (session key) that is only known by the group controller and all legitimate group members. In our scheme, all rekeying messages, except for unicast of an individual key, are transmitted without any encryption using one-way hash function and XOR operation. In our proposed scheme, nodes are capable of recovering lost session keys on their own, without requesting additional transmission from the group controller. The proposed scheme provides both backward and forward secrecy. We analyze the proposed scheme to verify that it satisfies the security and performance requirements for secure group communication.

Using polynomial-based key predistribution in distribution sensor networks for reference, this paper presents an efficient key predistribution scheme for Ad hoc networks: a multigrid-based key predistribution scheme. In this scheme we put forward the concept of multi-grid on which our key predistribution scheme is upbuilt, and the first time threshold scheme is introduced into the process of key transfer. The analysis in this paper indicates that this scheme has a number of nice properties, including high probability to establish pairwise keys, tolerance of node captures, and low communication overhea.

Recently, position-based routing has proven to be a scalable and efficient way for packet routing in mobile ad hoc networks. To enable position-based routing, a node must be able to discover the location of the intended destination node. This can typically be accomplished by a location service. By far there have been many efficient location service algorithms such as the DREAM, RLS, Homezone, GLS, DLM and HLS, but most of them have focused on the scalability and efficiency of algorithm while the security and privacy issues were vastly neglected. In this article, we propose a secure privacy-preserving hierarchical location service (SPPHLS) based on the HLS algorithm using the broadcast encryption scheme and broadcast authentication scheme. In the proposed secure location service scheme, the position privacy of nodes is protected and the security is promised. Finally, through simulation and analysis, we further show that the proposed scheme only introduces very moderate success rate degradation and query delay compared to the original HLS algorithm.

The framework of security communication among sensor nodes is the most important aspect and a basic research field of securing Wireless Sensor Networks. Many techniques have been developed recently to establish keys in sensor networks. Most of them are based on cluster topology. Based on the novel loop-topology, this paper proposes a new key establishment and rekeying scheme. The loop-based scheme has many advantages over cluster-based scheme. The analysis in this paper demonstrates its feasibility, efficiency and security for key establishment and maintenance in Wireless Sensor Networks.